<!DOCTYPE html>
<html>
<head>
  <title>Ruby Example</title>

  <script type="text/javascript">
    RubyModule = null;  // Global application object.
    statusText = 'NO-STATUS';
    rubyReady = false;

    // Indicate load success.
    function moduleDidLoad() {
      RubyModule = document.getElementById('ruby');
      form = document.getElementById('source-form');
      form.style.display = "block";
      updateStatus('SUCCESS');
    }

    function evalSource() {
      if (rubyReady) {
        RubyModule.postMessage('eval:' + document.getElementById("source").value);
      } else {
        throw "Not yet ready";
      }
      return false;
    }

    function RubyError(message) {
      this.message = message;
      this.toString = function() {
        return message;
      }
    }

    function FatalError(message) {
      this.message = message;
    }

    // The 'message' event handler.  This handler is fired when the NaCl module
    // posts a message to the browser by calling PPB_Messaging.PostMessage()
    // (in C) or pp::Instance.PostMessage() (in C++).  This implementation
    // simply displays the content of the message in an alert panel.
    function handleMessage(message_event) {
      var raw = message_event.data;
      var components;
      if (raw.indexOf("error") == 0) {
        components = raw.split(":", 2);
        throw new RubyError(components[1]);
      } else if (raw.indexOf("return") == 0) {
        components = raw.split(":", 2);
        document.getElementById("result").value = components[1];
      } else if (raw == "rubyReady") {
        rubyReady = true;
      } else {
        throw new FatalError(raw);
      }
    }

    // If the page loads before the Native Client module loads, then set the
    // status message indicating that the module is still loading.  Otherwise,
    // do not change the status message.
    function pageDidLoad() {
      if (RubyModule == null) {
        updateStatus('LOADING...');
      } else {
        // It's possible that the Native Client module onload event fired
        // before the page's onload event.  In this case, the status message
        // will reflect 'SUCCESS', but won't be displayed.  This call will
        // display the current message.
        updateStatus();
      }
    }

    // Set the global status message.  If the element with id 'statusField'
    // exists, then set its HTML to the status message as well.
    // opt_message The message test.  If this is null or undefined, then
    // attempt to set the element with id 'statusField' to the value of
    // |statusText|.
    function updateStatus(opt_message) {
      if (opt_message)
        statusText = opt_message;
      var statusField = document.getElementById('status_field');
      if (statusField) {
        statusField.innerHTML = statusText;
      }
    }
  </script>
</head>
<body onload="pageDidLoad()">

<h1>Native Client Module Ruby</h1>
<p>
  <!-- Load the published .nexe.  This includes the 'nacl' attribute which
  shows how to load multi-architecture modules.  Each entry in the "nexes"
  object in the .nmf manifest file is a key-value pair: the key is the
  instruction set architecture ('x86-32', 'x86-64', etc.); the value is a URL
  for the desired NaCl module.
  To load the debug versions of your .nexes, set the 'nacl' attribute to the
  _dbg.nmf version of the manifest file.

  Note: Since this NaCl module does not use any real-estate in the browser,
  it's width and height are set to 0.

  Note: The <EMBED> element is wrapped inside a <DIV>, which has both a 'load'
  and a 'message' event listener attached.  This wrapping method is used
  instead of attaching the event listeners directly to the <EMBED> element to
  ensure that the listeners are active before the NaCl module 'load' event
  fires.  This also allows you to use PPB_Messaging.PostMessage() (in C) or
  pp::Instance.PostMessage() (in C++) from within the initialization code in
  your NaCl module.
  -->
  <div id="listener">
    <script type="text/javascript">
      var listener = document.getElementById('listener');
      listener.addEventListener('load', moduleDidLoad, true);
      listener.addEventListener('message', handleMessage, true);
    </script>

    <embed name="nacl_module"
       id="ruby"
       width="0" height="0"
       src="ruby.nmf"
       type="application/x-nacl" />
    <form id="source-form" action="#" method="post" style="display:none"
      onsubmit="evalSource(); return false">
      <table>
        <tbody>
          <tr>
            <th>Source</th>
            <td>
              <textarea rows="10" cols="80" id="source"></textarea>
              <input type="submit" />
            </td>
          </tr>
          <tr>
            <th>Result</th>
            <td>
              <textarea rows="10" cols="80" id="result"></textarea>
            </td>
          </tr>
        </tbody>
      </table>
    </form>
  </div>
</p>

<h2>Status</h2>
<div id="status_field">NO-STATUS</div>
</body>
</html>
